Networking device port multiplexing

ABSTRACT

A system includes a first networking devices, a multiplexer, a second networking device, and a third networking device. The first networking device includes a pair of ports operational up to a first throughput. The multiplexer includes an input port connected to a port of the first networking device, and a pair of output ports. The second networking device includes an output port connected to a port of the first networking device and to an output port of the multiplexer, and operational up to a second throughput greater than the first throughput. The third networking device includes an output port connected to an output port of the multiplexer, and operational up to a third throughput no greater than the first throughput.

BACKGROUND

Networking speeds at which computing and other devices communicate withone another have continued to increase. Ten-megabit-per-second (mbps)speeds have given way to one-hundred-mbps speeds, and increasinglyone-gigabit-per-second (gbps) and ten-gbps speeds are common on wiredEthernet interfaces. In turn, wired Ethernet interfaces have beensupplanted and supplemented by fiber channel (FC) interfaces that canoperate at eight-, sixteen-, and even higher gbps speeds.

SUMMARY

An example system of the disclosure includes a first networking devicehaving a pair of ports operational up to a first throughput. The systemincludes a multiplexer having an input port connected to one of the pairof ports of the first networking device, and a pair of output ports. Thesystem includes a second networking device having an output portconnected to another one of the pair of ports of the first networkingdevice and to one of the pair of output ports of the multiplexer, andoperational up to a second throughput greater than the first throughput.The system includes a third networking device comprising an output portconnected to another one of the pair of output ports of the multiplexer,and operational up to a third throughput no greater than the firstthroughput.

Another example system of the disclosure includes multiplexers todirectly connect to a first networking device. The system includes asecond networking device external to the multiplexers and to directlyconnect to both the first networking device and the multiplexers. Thesystem includes third networking devices external to the multiplexers,to directly connect to the multiplexers, and to not directly connect tothe first networking device. The first networking device includes portsoperational up to a first throughput, the second networking deviceincludes output ports operational up to a second throughput greater thanthe first throughput, and the third networking devices include outputports operational up to a third throughput no greater than the firstthroughput. The multiplexers are to multiplex each port of the firstnetworking device to which the multiplexers are connected to the secondnetworking device or to one of the third networking devices.

An example networking device of the disclosure includes multiplexers todirectly connect to a different networking device. The networking deviceincludes first output ports to directly connect to the differentnetworking device and to directly connect to the multiplexers, andsecond output ports to directly connect to the multiplexers and to notdirectly connect to the different networking device. The differentnetworking device includes ports operational up to a first throughput.The first output ports are operational up to a second throughput greaterthan the first throughput, and the second output ports are operationalup to a third throughput no greater than the first throughput. Themultiplexers are to multiplex each port of the first networking deviceto which the multiplexers are connected to one of the first output portsor to one of the second output ports.

An example method of the disclosure is performable in a system having afirst networking device, a multiplexer, a second networking device, anda third networking device. The method includes the following to operatean output port of the second networking device at a first throughputgreater than a throughput of each of a plurality of ports of the firstnetworking device. A first port of the ports of the first networkingdevice is multiplexed from the first networking device to the secondnetworking device, using the multiplexer, such that an output port ofthe third networking device to which the multiplexer is connected isnon-operational. The first port is bridged with a second port of theports of the first networking device directly connected to the secondnetworking device to operate the output port of the second networkingdevice at the first throughput.

The method includes the following to operate the output port of thesecond networking device at a second throughput no greater than thethroughput of each of the plurality of ports of the first networkingdevice. The second port of the first networking device directlyconnected to the second networking device is used without bridging thesecond port with the first port of the first networking device, tooperate the output port of the second networking device at the firstthroughput. The first port of the first networking device is multiplexedfrom the first networking device to the third networking device, usingthe multiplexer, such that the output port of the third networkingdevice to which the multiplexer is connected is operational at up to thethroughput of each of the plurality of ports of the first networkingdevice.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The drawings referenced herein form a part of the specification.Features shown in the drawing illustrate only some embodiments of thedisclosure, and not of all embodiments of the disclosure, unless thedetailed description explicitly indicates otherwise, and readers of thespecification should not make implications to the contrary.

FIG. 1 is a diagram of an example system in which networking deviceports are multiplexed.

FIG. 2 is a diagram of another example system in which networking deviceports are multiplexed.

FIG. 3 is a flowchart of an example method for operating a system inwhich networking device ports are multiplexed.

DETAILED DESCRIPTION

The following detailed description of exemplary embodiments of thedisclosure refers to the accompanying drawings that form a part of thedescription. The drawings illustrate specific exemplary embodiments inwhich the disclosure may be practiced. The detailed description,including the drawings, describes these embodiments in sufficient detailto enable those skilled in the art to practice the disclosure. Thoseskilled in the art may further utilize other embodiments of thedisclosure, and make logical, mechanical, and other changes withoutdeparting from the spirit or scope of the disclosure. Readers of thefollowing detailed description should, therefore, not interpret thedescription in a limiting sense, and only the appended claims define thescope of the embodiment of the disclosure.

As noted in the background section, networking speeds have continued toincrease. However, for legacy, cost and other reasons, networkingadministrators may encounter situations in which networking devices ofdifferent speeds have to be interconnected with one another. Forexample, a wired Ethernet switch may have eight ten-gigabit-per-second(gbps) ports, and the devices that are to connect to this Ethernetswitch may include devices also having ten-gbps wired Ethernet ports,devices having eight-gbps fiber channel (FC) ports, and devices havingsixteen-gbps FC ports. As such, an Ethernet-to-FC device may be employedso that the devices having the FC ports can be connected to the wiredEthernet ports of the Ethernet switch.

It may not be known a priori whether the Ethernet-to-FC device willconnect sixteen-gbps FC devices, eight-gbps FC devices, or ten-gbpswired Ethernet devices, however. To ensure that the sixteen-gbps FCdevices are able to communicate at their rated throughput, theEthernet-to-FC device may have four output ports that each bridges twoof the ten gbps ports of the wired Ethernet switch. Therefore, if asixteen-gbps FC device is connected to an output port, this device isable to communicate at its rated maximum throughput. However, if aneight-gbps FC device or a ten gbps wired Ethernet device is insteadconnected to an output port, the bandwidth provided by bridging two ofthe ten-gbps ports of the wired Ethernet switch is effectively wasted.

Techniques disclosed herein overcome this problem. In the above example,four multiplexers are connected between four of the ports of the wiredEthernet switch and the Ethernet-to-FC device. The other four ports ofthe wired Ethernet switch are connected directly to the Ethernet-to-FCdevice. If an output port of the Ethernet-to-FC device is connected to asixteen-gbps FC device, then one of the multiplexers multiplexes itswired Ethernet switch port to the Ethernet-to-FC device. TheEthernet-to-FC device bridges this multiplexed port with one of thedirectly connected Ethernet switch ports to provide the sixteen-gbps FCdevice its full maximum throughput.

However, if an output port of the Ethernet-to-FC device is not used, oris connected to an eight-gbps FC device or a ten-gbps wired Ethernetdevice, then the multiplexer does not multiplex its wired Ethernetswitch port to the Ethernet-to-FC device for bridging purposes. Thiswired Ethernet switch port can instead be connected via the multiplexerto another eight-gbps FC device or ten-gbps wired Ethernet device. Assuch, bridging two wired Ethernet switch ports is achieved just whennecessary to provide a throughput greater than the throughput of anyindividual wired Ethernet switch port. The bandwidth provided by thewired Ethernet switch is not wasted, and is maximally usable.

FIG. 1 shows an example system 100. The system 100 includes networkingdevices 102, 104, and 106A, 106B, 106C, and 106D, the latter four ofwhich are collectively referred to as the networking devices 106. Thesystem 100 also includes multiplexers 108A, 108B, 108C, and 108D, whichare collectively referred as to the multiplexers 108. More generally,there are one or more networking devices 106, and one or moremultiplexers 108. It is noted that the description herein is primarilymade with respect to transmission paths from the networking device 102to the networking devices 104 and 106, but applies equally totransmission paths from the networking devices 104 and 106 to thenetworking device 102.

The networking device 102 may be a wired Ethernet switch, and includeseights ports 110A, 110B, 110C, 110D, 110E, 110F, 110G, and 110H, whichare collectively referred to as the ports 110. More generally, there areat least two ports 110. Each port 110 is operational up to a firstthroughput. For example, each port 110 may be a wired Ethernet port thatis able to support ten gbps. It is noted that usage of the terminologyport is used herein synonymously with the term interface.

The networking device 104 may be an Ethernet-to-FC device, such as anEthernet-to-FC bridge device. The networking device 104 may be aphysical networking layer (PHY) device, or another type of networkingdevice. The networking device 104 includes eight input ports 112A, 112B,112C, 112D, 112E, 112F, 112G, and 112H, which are collectively referredto as the input ports 112. More generally, there are at least two inputports 112. The input ports 112 can be the same type of port as the ports110 of the networking device 102, such as ten-gbps wired Ethernet ports.

The networking device 104 includes four output ports 114A, 114B, 114C,and 114D, which are collectively referred to as the output ports 114.More generally, there is at least one output port 114. Each output port114 is operational up to a second throughput greater than the firstthroughput at which the ports 110 of the networking device 102 canmaximally operate. For example, each output port 114 may be able tosupport a ten-gbps wired Ethernet port, an eight-gbps FC port, or asixteen-gbps FC port.

The networking devices 106 may be PHY devices, retiming devices, orother types of networking devices. The four networking devices 106include four input ports 116A, 116B, 116C, and 116D, respectively, whichare collectively referred to as the input ports 116. In general, eachnetworking device 106 has at least one input port 116. The input ports116 can be the same type of port as the ports 110 of the networkingdevice 102, such as ten-gbps wired Ethernet ports.

The four networking devices 106 include four output ports 118A, 118B,118C, and 118D, respectively, which are collectively referred to as theoutput ports 118. In general, each networking device 106 has at leastone output port 118. Each output port 118 is operational up to a thirdthroughput no greater than the first throughput at which the ports 110of the networking device 102 can maximally operate. For example, eachoutput port 118 may be the same type of port as the ports 110 of thenetworking device 102, such as ten-gbps wired Ethernet ports.

The four multiplexers 108 include four input ports 120A, 120B, 120C, and120D, respectively, which are collectively referred to as the inputports 120. The four multiplexers 108 include eight output ports 122A and122B, 122C and 122D, 122E and 122F, and 122G and 122H, respectively,which are collectively referred to as the output ports 122. In general,each multiplexer 108 has at least one input port 120 and at least twooutput ports 122. The input ports 120 and the output ports 122 can bethe same type of port as the ports 110 of the networking device 102,such as ten-gbps wired Ethernet ports.

Four ports 110A, 110B, 110C, and 110D of the networking device 102 aredirectly connected to four input ports 112A, 112B, 112C, and 112D,respectively, of the networking device 104. The other four ports 110E,110F, 110G, and 110H of the networking device 102 are directly connectedto the four input ports 120, respectively, of the multiplexers 108. Fouroutput ports 122A, 122C, 122E, and 122G of the multiplexers 108 aredirectly connected to the other four input ports 112E, 112F, 112G, and112H, respectively, of the networking device 104. The other four outputports 122B, 122D, 122F, and 122H of the multiplexers 108 are directlyconnected to the four input ports 116, respectively, of the networkingdevices 106.

As noted, the four input ports 112A, 112B, 112C, and 112D of thenetworking device 104 are directly connected to the four ports 110A,110B, 110C, and 110D, respectively, of the networking device 102. Bycomparison, the other input ports 112E, 112F, 112G, and 112H of thenetworking device 104 are indirectly connected to the other four ports110E, 110F, 110G, and 110H, respectively, of the networking device 102,via the multiplexers 108. Similarly, the four input ports 116 of thenetworking device 106 are indirectly connected to the same four ports110E, 110F, 110G, and 110H, respectively, of the networking device 102,via the multiplexers 108.

Within the networking device 104, the input ports 112A and 112E areconnected to the output port 114A. Specifically, just the input port112A can be connected to the output port 114A, or the input ports 112Aand 112E can be bridged together and connected to the output port 114A.Each other output port 114 is connected in this same manner to two inputports 112 within the networking device 104. The output port 114B isconnected to the input ports 112B and 112F, the output port 114C isconnected to the input ports 112C and 112G, and the output port 114D isconnected to the input ports 112D and 112H.

By comparison, within each networking device 106, each output port 118is connected to one corresponding input port 116. Specifically, theoutput port 118A of the networking device 106A is connected to the inputport 116A of the networking device 106A. The output port 118B of thenetworking device 106B is connected to the input port 116B of thenetworking device 106B, and the output port 118C of the networkingdevice 106C is connected to the input port 116C of the networking device106C. The output port 118D of the networking device 106D is connected tothe input port 116D of the networking device 106D.

The example system 100 works as follows. If an output port 114 of thenetworking device 104 has to operate at a throughput greater than thefirst throughput of each port 110 of the networking device 102, then twoports 110 are bridged together within the networking device 104 toprovide the desired throughput. One of these two ports 110 is directlyconnected to the networking device 104, whereas the other of these twoports 110 is indirectly connected to the networking device 104 via amultiplexer 108 multiplexing the port 110 in question to the networkingdevice 104.

For example, if the output port 114A of the networking device 104 has tooperate at a throughput greater than the first throughput of the eachport 110 of the networking device 102, then the ports 110A and 110E arebridged together within the networking device 104 to provide the desiredthroughput. The port 110A is directly connected to the networking device104. The port 110E is indirectly connected to the networking device 104via the multiplexer 108A multiplexing the port 110E to the networkingdevice 104.

The above-described operation is referred as a bridging operational modeof the output port 114A. Each output port 114 is able to operate in thebridging operational mode irrespective of whether any other output port114 is operating in this mode. When an output port 114 is operating inthe bridging operational mode, however, the output port 118 of one ofthe networking devices 106 is non-operational. This is because thenetworking device 106 in question is not connected to any port 110 ofthe networking device 102, because a multiplexer 108 has multiplexed theport 110 that would otherwise be connected to this networking device 106to the networking device 104 instead.

In the above example, the multiplexer 108A has multiplexed the port 110Eof the networking device 102 to the networking device 104. Themultiplexer 108A is able to multiplex the port 110E to either thenetworking device 104 or the networking device 106A. Therefore, becausethe port 110E has been multiplexed to the networking device 104, theport 110E is not multiplexed to the networking device 106A. The outputport 118A of the networking device 106A is thus non-operational, becausethe networking device 106A is not connected to the networking device102.

Each output port 114 of the networking device 104 is also able tooperate in a non-bridging operational mode, again irrespective ofwhether any other output port 114 is operating in this mode. Thisoperational mode works as follows. If an output port 114 just has tooperate at a throughput no greater than the first throughput of eachport 110 of the networking device 102, then two ports 110 are notbridged together within the networking device 104. Rather, just one port110 is used to provide this desired throughput, specifically the port110 that is directly connected to the networking device 104.

For example, the output port 114A of the networking device 104 may haveto operate just at a throughput no greater than the first throughput ofeach port 110 of the networking device 102. Therefore, the ports 110Aand 110E do not have to be bridged together within the networking device104. Rather, just the port 110A directly connected to the networkingdevice 104 is used to provide this throughput.

When an output port 114 is operating in the non-bridging operationalmode, the output port 118 of one of the networking devices 106 becomesoperational. This is because the networking device 106 in question canbe connected to a port 110 of the networking device 102, since the port110 is not needed to provide the desired throughput at the output port114 in question of the networking device 104. As such, the multiplexer108 multiplexes the port 110 in question to this networking device 106,instead of to the networking device 104.

In the above example, the multiplexer 108A multiplexes the port 110E ofthe networking device 102 to the networking device 106A. The output port118A of the networking device 106A is thus operational, because thenetworking device 106A is connected to the networking device 102. Theoutput port 118A can provide a throughput no greater than the firstthroughput of the port 110E itself.

Switching an output port 114 of the networking device 104 between thebridging operational mode and the non-bridging operational mode can beachieved in a number of different ways. The networking device 104 mayhave built-in logic to provide this switching capability. The logic maydetect whether a device has been connected to an output port 114 thatcan support a greater throughput than any one port 110 of the networkingdevice 102 can provide. If so, then the output port 114 may beconfigured to bridge together two ports 110 as described, and if not,then the output port 114 may be configured to use the port 110 to whichthe networking device 104 is directly connected.

Switching an output port 114 between the two operational modes can alsobe specified via user configuration, such that a given output port 114is specified by the user to operate in a particular operational moderegardless of whether a device is connected to the output port 114 andregardless of the type of device that is connected to the output port114. Switching an output port 114 can be achieved by a managementcomponent as well. The management component may be software, hardware,or a combination of software and hardware that encodes desired logic,and which can be internal or external to the networking device 104.

In cooperation with an output port 114 operating in a particularoperational mode, a corresponding multiplexer 108 may have toappropriately multiplex a port 110 of the networking device 102 to thenetworking device 104. Specifically, when an output port 114 isoperating in the bridging operational mode, the correspondingmultiplexer 108 has to multiplex a port 110 of the networking device 102that the networking device 104 bridges with one of the directlyconnected ports 110. When an output port 114 is operating in thenon-bridging operational mode, from the perspective of the networkingdevice 104 it does not matter whether the multiplexer 108 hasmultiplexed a port 110 of the networking device 102 to the networkingdevice 104 or not. However, by default, it can be desirable for thismultiplexer 108 to multiplex the port 110 in question to one of thenetworking devices 106, so that this networking device 106 can takeadvantage of the bandwidth afforded by the port 110 and can beoperational.

The multiplexers 108 can have their multiplexing functionalitycontrolled to select whether the ports 110 are (independently)multiplexed to the networking device 104 or to the networking devices106 in a number of different ways. For example, the networking device104 may be communicatively connected to a select line of eachmultiplexer 108, and assert (or not assert) the select line when thenetworking device 104 needs to bridge the port 110 to which themultiplexer 108 in question is connected. As a second example, a usermay manually configure each multiplexer 108, independently ofconfiguration of the operational mode in which each output port 114 ofthe networking device 104 is to operate. As a third example, themanagement component may appropriately configure the multiplexers 108 inaccordance its configuration of the output ports 114 of the networkingdevice 104, depending on which (if any) output ports 114 are operatingin the bridging operational mode.

FIG. 2 shows another example system 100. In the system 100 of FIG. 2,the multiplexers 108 are internal to the networking device 104, asopposed to being external to the networking device 104 as in FIG. 1. Inone implementation, the multiplexers 108 may be implemented in FIG. 2 aspart of the same discrete integrated circuit (IC) within which the logicof the networking device 104, if any, is implemented.

Furthermore, in FIG. 2 the networking devices 106 are effectivelyinternalized within the networking device 104, and thus are representedby dotted lines in FIG. 2, as opposed to being external to thenetworking device 104 as in FIG. 1. Specifically, the output ports 118are part of the networking device 104 in the system 100 of FIG. 2, andthe input ports 116 may not be present. Otherwise, though, the system100 operates in FIG. 2 in the same manner as the system 100 does in FIG.1.

In conclusion, FIG. 3 shows an example method 300 that summarizesexample operation of the system 100 of both FIGS. 1 and 2. The method300 is performed for an output port 114 of the networking device 104.Part 302 is performed to operate this output port 114 in the bridgingoperational mode, at a throughput greater than the throughput of theports 110 of the networking device 102. Part 304 is performed to operatethe output port 114 in the non-bridging operational mode, at athroughput no greater than the throughput of the ports 110 of thenetworking device 102.

In part 302, a multiplexer 108 is used to multiplex a port 110 of thenetworking device 102 to the networking device 104 (306). Thismultiplexed port 110 is bridged at the networking device 104 with a port110 of the networking device 102 to which the networking device 104 isdirectly connected (308). As such, the output port 114 can operate at athroughput greater than the throughput of either of these ports 110.However, the output port 118 of the networking device 106 to which themultiplexer 108 can also multiplex a port 110 becomes non-operational.

In part 304, the multiplexer 108 is used to multiplex the port 110 ofthe networking device 102 to the networking device 106 instead (310).The port 110 of the networking device 102 to which the networking device104 is directly connected is thus used by itself at the networkingdevice 104, without being bridged to any other port 110 (312). As such,the output port 114 of the networking device 104 can operate at athroughput no greater than the throughput of the directly connected port110. However, the output port 118 of the networking device 106 is nowoperational, and can also operate at a throughput no greater than thethroughput of the multiplexed port 110.

It is noted that, as can be appreciated by one those of ordinary skillwithin the art, aspects of the present invention may be embodied as asystem, method or computer program product. Accordingly, aspects of theembodiments of the invention may take the form of an entirely hardwareembodiment, an entirely software embodiment (including firmware,resident software, micro-code, etc.) or an embodiment combining softwareand hardware aspects that may all generally be referred to herein as a“circuit,” “module” or “system.” Furthermore, aspects of the presentinvention may take the form of a computer program product embodied inone or more computer readable medium(s) having computer readable programcode embodied thereon.

Any combination of one or more computer readable medium(s) may beutilized. The computer readable medium may be a computer readable signalmedium or a computer readable storage medium. A computer readablestorage medium may be, for example, but not limited to, an electronic,magnetic, optical, electromagnetic, infrared, or semiconductor system,apparatus, or device, or any suitable combination of the foregoing. Morespecific examples (a non-exhaustive list) of the computer readablestorage medium include the following: an electrical connection havingone or more wires, a portable computer diskette, a hard disk, a randomaccess memory (RAM), a read-only memory (ROM), an erasable programmableread-only memory (EPROM or Flash memory), an optical fiber, a portablecompact disc read-only memory (CD-ROM), an optical storage device, amagnetic storage device, or any suitable combination of the foregoing.In the context of this document, a computer readable storage medium maybe any tangible medium that can contain, or store a program for use byor in connection with an instruction execution system, apparatus, ordevice.

A computer readable signal medium may include a propagated data signalwith computer readable program code embodied therein, for example, inbaseband or as part of a carrier wave. Such a propagated signal may takeany of a variety of forms, including, but not limited to,electro-magnetic, optical, or any suitable combination thereof. Acomputer readable signal medium may be any computer readable medium thatis not a computer readable storage medium and that can communicate,propagate, or transport a program for use by or in connection with aninstruction execution system, apparatus, or device. Program codeembodied on a computer readable medium may be transmitted using anyappropriate medium, including but not limited to wireless, wireline,optical fiber cable, RF, etc., or any suitable combination of theforegoing.

In general, a computer program product includes a computer-readablemedium on which one or more computer programs are stored. Execution ofthe computer programs from the computer-readable medium by one or moreprocessors of one or more hardware devices causes a method to beperformed. For instance, the method that is to be performed may be oneor more of the methods that have been described above.

The computer programs themselves include computer program code. Computerprogram code for carrying out operations for aspects of the presentinvention may be written in any combination of one or more programminglanguages, including an object oriented programming language such asJava, Smalltalk, C++ or the like and conventional procedural programminglanguages, such as the “C” programming language or similar programminglanguages. The program code may execute entirely on the user's computer,partly on the user's computer, as a stand-alone software package, partlyon the user's computer and partly on a remote computer or entirely onthe remote computer or server. In the latter scenario, the remotecomputer may be connected to the user's computer through any type ofnetwork, including a local area network (LAN) or a wide area network(WAN), or the connection may be made to an external computer (forexample, through the Internet using an Internet Service Provider).

Aspects of the present invention have been described above withreference to flowchart illustrations and/or block diagrams of methods,apparatus (systems) and computer program products according toembodiments of the invention. It will be understood that each block ofthe flowchart illustrations and/or block diagrams, and combinations ofblocks in the flowchart illustrations and/or block diagrams, can beimplemented by computer program instructions. These computer programinstructions may be provided to a processor of a general purposecomputer, special purpose computer, or other programmable dataprocessing apparatus to produce a machine, such that the instructions,which execute via the processor of the computer or other programmabledata processing apparatus, create means for implementing thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

These computer program instructions may also be stored in a computerreadable medium that can direct a computer, other programmable dataprocessing apparatus, or other devices to function in a particularmanner, such that the instructions stored in the computer readablemedium produce an article of manufacture including instructions whichimplement the function/act specified in the flowchart and/or blockdiagram block or blocks.

The computer program instructions may also be loaded onto a computer,other programmable data processing apparatus, or other devices to causea series of operational steps to be performed on the computer, otherprogrammable apparatus or other devices to produce a computerimplemented process such that the instructions which execute on thecomputer or other programmable apparatus provide processes forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks.

The flowchart and block diagrams in the figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof code, which comprises one or more executable instructions forimplementing the specified logical function(s). It should also be notedthat, in some alternative implementations, the functions noted in theblock may occur out of the order noted in the figures. For example, twoblocks shown in succession may, in fact, be executed substantiallyconcurrently, or the blocks may sometimes be executed in the reverseorder, depending upon the functionality involved. It will also be notedthat each block of the block diagrams and/or flowchart illustration, andcombinations of blocks in the block diagrams and/or flowchartillustration, can be implemented by special purpose hardware-basedsystems that perform the specified functions or acts, or combinations ofspecial purpose hardware and computer instructions.

It is finally noted that, although specific embodiments have beenillustrated and described herein, it will be appreciated by those ofordinary skill in the art that any arrangement calculated to achieve thesame purpose may be substituted for the specific embodiments shown. Thisapplication is thus intended to cover any adaptations or variations ofembodiments of the present invention. As such and therefore, it ismanifestly intended that this invention be limited only by the claimsand equivalents thereof.

We claim:
 1. A system comprising: a first networking device comprising apair of ports; a multiplexer comprising an input port connected to oneof the pair of ports of the first networking device, and a pair ofoutput ports; and a second networking device comprising an output portconnected to another one of the pair of ports of the first networkingdevice and to one of the pair of output ports of the multiplexer.
 2. Thesystem of claim 1, wherein in a first operational mode, the output portof the second networking device is configured to operate at greater thanthe first throughput, and the multiplexer is configured to multiplex thefirst networking device to the second networking device.
 3. The systemof claim 2, further comprising: a third networking device comprising anoutput port connected to another one of the pair of output ports of themultiplexer, wherein in the first operational mode, the multiplexer isconfigured to not multiplex the first networking device to the thirdnetworking device.
 4. The system of claim 2, wherein in the firstoperational mode, the second networking device bridges the pair of portsof the first networking device to operate the output port of the secondnetworking device at greater than the first throughput.
 5. The system ofclaim 2, further comprising: a third networking device comprising anoutput port connected to another one of the pair of output ports of themultiplexer, wherein in the first operational mode, the third networkingdevice is not connected to the first networking device, such that theoutput port of the third networking device is non-operational.
 6. Thesystem of claim 1, further comprising: a third networking devicecomprising an output port connected to another one of the pair of outputports of the multiplexer, wherein in a second operational mode, theoutput port of the second networking device is configured to operate atno greater than the first throughput, and the multiplexer is configuredto multiplex the first networking device to the third networking device.7. The system of claim 6, wherein in the second operational mode, themultiplexer is configured to not multiplex the first networking deviceto the second networking device.
 8. The system of claim 6, wherein inthe second operational mode, the second networking device does notbridge the pair of ports of the first networking device to operate theoutput port of the second networking device at no greater than the firstthroughput.
 9. The system of claim 6, wherein in the second operationalmode, the third networking device is connected to the first networkingdevice, such that the output port of the third networking device isoperational at up to the first throughput.
 10. The system of claim 1,further comprising: a third networking device comprising an output portconnected to another one of the pair of output ports of the multiplexer,wherein the multiplexer is one of external to the second networkingdevice and internal to the second networking device, and wherein thethird networking devices are one of external to the second networkingdevice and internal to the second networking device.
 11. The system ofclaim 1, wherein the ports of the first networking device are wiredEthernet ports, and the output port of the second networking device is afiber channel or Ethernet port.
 12. A system comprising: a plurality ofmultiplexers to directly connect to a first networking device; and asecond networking device external to the multiplexers and to directlyconnect to both the first networking device and the multiplexers,wherein the first networking device comprises a plurality of ports, andthe second networking device, and wherein the multiplexers are tomultiplex each port of at least a subset of the ports the firstnetworking device to which the multiplexers are connected to the secondnetworking device.
 13. The system of claim 12, wherein in a bridgingmode of a given output port of the ports of the second networkingdevice, the given output port is configured to operate at greater thanthe first throughput, the multiplexers are configured to multiplex agiven port of the ports of the first networking device to the secondnetworking device, the second networking device is to bridge the givenport and another port of the first networking device to operate thegiven output port at greater than the first throughput.
 14. The systemof claim 12, further comprising: a plurality of third networking devicesexternal to the multiplexers, to directly connect to the multiplexers,and to not directly connect to the first networking device, wherein thethird networking devices comprise a plurality of output ports, whereinthe multiplexers are to multiplex each port of a different subset of theports of the first networking device to one of the third networkingdevices, wherein in a non-bridging mode of a given output port of theports of the second networking device, the given output port isconfigured to operate at no greater than the first throughput, themultiplexers are configured to multiplex a given port of the ports ofthe first networking device to a given third networking device of thethird networking devices and not to the second networking device, thesecond networking device uses another port of the first networkingdevice without bridging the given port with the another port to operatethe given output port at no greater than the first throughput, and theoutput port of the given third networking device is operational at up tothe first throughput.
 15. The system of claim 12, wherein the ports ofthe first networking device are wired Ethernet ports, and the outputports of the second networking device are each a fiber channel orEthernet port.
 16. A networking device comprising: a plurality ofmultiplexers to directly connect to a different networking device; aplurality of first output ports to directly connect to the differentnetworking device and to directly connect to the multiplexers; aplurality of second output ports to directly connect to the multiplexersand to not directly connect to the different networking device; whereinthe different networking device comprises a plurality of ports, andwherein the multiplexers are to multiplex each port of the firstnetworking device to which the multiplexers are connected to one of thefirst output ports or to one of the second output ports.
 17. Thenetworking device of claim 16, wherein in a bridging mode of a givenfirst output port of the first output ports, the given first output portis configured to operate at greater than the first throughput, themultiplexers are configured to multiplex a given port of the ports ofthe different networking device to the given first output port and notto a given second output port of the second output ports, the given portand another port of the different networking device are bridged tooperate the given first output port at greater than the firstthroughput, and the given second output port is non-operational.
 18. Thenetworking device of claim 16, wherein in a bridging mode of a givenfirst output port of the first output ports, the given first output portis configured to operate at no greater than the first throughput, themultiplexers are configured to multiplex a given port of the ports ofthe different networking device to a given second output port of thesecond output ports and not to the given first output port, another portof the different networking device is used without being bridged withthe given port to operate the given first output port at no greater thanthe first throughput, and the given second output port is operational atup to the first throughput.
 19. The networking device of claim 16,wherein the ports of the different networking device are wired Ethernetports, the first output ports are each a fiber channel or Ethernet port,and the second output ports are wired Ethernet ports.
 20. A methodperformable in a system comprising a first networking device, amultiplexer, and a second networking device, the method comprising: tooperate an output port of the second networking device in a first mode,multiplexing a first port of a plurality of ports of the firstnetworking device from the first networking device to the secondnetworking device, using the multiplexer; bridging the first port with asecond port of the ports of the first networking device directlyconnected to the second networking device; and to operate the outputport of the second networking device in a second mode, using the secondport of the first networking device directly connected to the secondnetworking device, without bridging the second port with the first portof the first networking device.